来自数组的 Elasticsearch 多个聚合

Question

如何在一个查询中动态组合多个聚合？

我知道要“硬编码”：

request.Aggregations = new TermsAggregation("agg_field1") {
    Field = "field1"
}
&& new TermsAggregation("agg_field2") {
    Field = "field2"
};

但由于我使用包含字段的数组，因此我需要类似以下内容。但我收到编译器错误，因为运算符 '&=' 无法组合 'AggregationDictionary' 和 'TermsAggregation'：

string[] Fields = new[]{ "field1", "field2" }
foreach (string sField in Fields)
{
    request.Aggregations &= new TermsAggregation("agg_" + sField)
    {
        Field = sField
    };
}

我有“产品”、“品牌”、“型号”等字段的文章数据。 对于这个字段，我想通过聚合获得每个不同的值。它用于显示三个组合框以及每个字段的可能值。

Answer 1

您可以通过几种不同的方式来构建聚合集合。最接近你想要做的事情是

var request = new SearchRequest<object>();

string[] Fields = new[] { "field1", "field2" };
AggregationBase aggregations = null;  
foreach (string sField in Fields)
{
    var termsAggregation = new TermsAggregation("agg_" + sField)
    {
        Field = sField
    };

    if (aggregations == null)
    {
        aggregations = termsAggregation;
    }
    else
    {
        aggregations &= termsAggregation;
    }
}

request.Aggregations = aggregations;

client.Search<object>(request);

构建以下查询

{
  "aggs": {
    "agg_field1": {
      "terms": {
        "field": "field1"
      }
    },
    "agg_field2": {
      "terms": {
        "field": "field2"
      }
    }
  }
}